HR: 1340h
AN: B33A-0862    [Abstracts]
TI: Nutrient Dynamics and Carbon Microbial Mineralization Processes in the Pichavaram Intertidal Mangrove Sediments from India
AU: * Mathukumalli, B
EM: mbkprasad@gmail.com
AF: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
AB: Various nutrient parameters of the mangrove water were analyzed for one year (July 2003-June2004) to delineate the driving forces behind the biogeochemical nutrient dynamics in the Pichavaram mangrove waters of south east coast of India. With few exceptions, the over all trend was higher concentrations of nutrients in monsoon and post-monsoon periods. Regression analyses between salinity and various nutrients explain that salinity had firm control over the nutrient distribution in the mangrove water. Stoichiometric ratios deviated greatly from the Redfield ratio, reflecting nutrient behavior that was non-conservative because of long residence time and high primary productivity associated with organic matter decomposition. Microbial nutrient mineralization rates were estimated at two different locations (i.e. impacted and un-impacted). Sulfate reduction is the major microbial mineralization pathway followed by metal (Fe-Mn) and aerobic decomposition. Total carbon oxidation (TCOX) were calculated and found that TCOX rates were higher in the pristine A. marina zone than in the two impacted stands (43 and 79 mol C m−2 y−1); rates of total carbon oxidation in the R. apiculata forest averaged 75 mol C m−2 y−1. The sulfate reduction was peaked at the surface to a depth of 1 m, leading to little carbon burial (~5% of total C input). The microbial activities are actively dampened by the anthropogenic activities and it alters the plant-soil relationship which ultimately influences the biogeochemical cycling of nutrients in the coastal environment.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0419 Biomineralization
DE: 0428 Carbon cycling (4806)
DE: 0458 Limnology (1845, 4239, 4942)
DE: 0470 Nutrients and nutrient cycling (4845, 4850)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting